Reduced VOC coatings using chemically modified hyperbranched polymers

Abstract

Reduced VOC coatings are provided that include small amounts of modified hyperbranched polymers added and reduced solvents to reduce VOC levels by as much as 30% and more. The reduced VOC coatings have substantially improved flow and performance characteristics over comparable commercially available reduced VOC coatings.

1. A reduced Volatile Organic Compound coating, comprising:
 at least one pigment; 
 at least one resin, wherein a portion of the at least one resin comprises at least one thermoplastic polymer and wherein another portion of the at least one resin comprises at least one modified hyperbranched polymer, the modified hyperbranched polymer comprising a polar hyperbranched polymer that has been esterified by at least one organic acid; and 
 at least one added solvent; 
 wherein the modified hyperbranched polymer is prepared by:
 providing a given thermoplastic polymer resin; 
 providing a polar hydroxyl terminated hyperbranched polymer, the hyperbranched polymer having a viscosity lower than a viscosity of the linear thermoplastic polymer of the given resin; 
 determining a number of hydroxyl ends in the hyperbranched polymer; 
 determining a percentage of the hydroxyl ends to be modified; 
 determining a stoichiometric amount of at least one acid to be used to modify the polar hydroxyl terminated hyperbranched polymer, the stoichiometric amount being calculated according to the number of hydroxyl ends in the hyperbranched polymer and the percentage of hydroxyl ends to be modified; and 
 esterifying the polar hyperbranched polymer by adding the determined amount of the at least one acid to the polar hyperbranched polymer; and 
 replacing a portion of the linear thermoplastic polymer in the given resin with the at least one modified hyperbranched polymer; and 
 
 wherein up to about 13% of the linear thermoplastic polymer is replaced by the at least one modified hyperbranched polymer. 
 
     
     
       2. The reduced VOC coating of  claim 1 , wherein the reduced VOC coating comprises:
 the at least one pigment in an amount between about 28% to about 32% by weight of the reduced VOC coating; 
 the at least one resin in an amount between about 34% to about 39% by weight of the reduced VOC coating, which includes the linear thermoplastic polymer in the given resin and the at least one modified hyperbranched polymer that has replaced a portion of the linear thermoplastic polymer in the given resin; and 
 the at least one added solvent in an amount between about 15% to about 20% by weight of the reduced VOC coating. 
 
     
     
       3. The reduced VOC coating of  claim 2 , wherein the at least one pigment comprises about 30% by weight of the reduced VOC coating, the at least one resin comprises about 37% by weight of the reduced VOC coating, and the at least one added solvent comprises about 18% of the reduced VOC coating. 
     
     
       4. The reduced VOC coating of  claim 1 , wherein the reduced VOC coating comprises:
 the at least one pigment in an amount between about 33% to about 39% by weight of the reduced VOC coating; 
 the at least one resin in an amount between about 35% to about 40% by weight of the reduced VOC coating which includes the linear thermoplastic polymer in the given resin and the at least one modified hyperbranched polymer that has replaced a portion of the linear thermoplastic polymer in the given resin; and 
 the at least one added solvent in an amount between about 20% to about 25% by weight of the reduced VOC coating. 
 
     
     
       5. The reduced VOC coating of  claim 4 , wherein the at least one pigment comprises about 37% by weight of the coating, the at least one resin comprises about 39% by weight of the reduced VOC coating, and the at least one added solvent comprises about 22% of the reduced VOC coating. 
     
     
       6. The reduced VOC coating of  claim 1 , wherein the at least one modified hyperbranched polymer has replaced about 2% to about 6% by weight of the linear thermoplastic polymer in the given resin. 
     
     
       7. The reduced VOC coating of  claim 1 , wherein the at least one resin comprises about 70% to about 85% solids. 
     
     
       8. The reduced VOC coating of  claim 1 , wherein the polar hyperbranched polymer comprises hyperbranched polymers with OH terminal functional groups and having a hydroxyl functionality between 16 and 128. 
     
     
       9. The reduced VOC coating of  claim 1 , wherein the at least one acid is selected from the group consisting of propionic acid, hexanoic acid, octanoic acid, and decanoic acid. 
     
     
       10. A method of reducing Volatile Organic Compounds in a given coating based on at least one linear thermoplastic polymer, at least one added solvent and at least one pigment, comprising the steps of:
 modifying the polarity of at least one hydroxyl terminated hyperbranched polymer to make at least one modified hyperbranched polymer, wherein modifying the polarity of the hyperbranched polymer comprises:
 providing a polar hydroxyl terminated hyperbranched polymer, the hyperbranched polymer having a viscosity lower than a viscosity of the linear thermoplastic polymer; 
 determining a number of hydroxyl ends in the hyperbranched polymer; 
 determining a percentage of the hydroxyl ends to be modified; 
 determining a stoichiometric amount of at least one acid to be used to modify the polar hydroxyl terminated hyperbranched polymer, the stoichiometric amount being calculated according to the number of hydroxyl ends in the hyperbranched polymer and the percentage of hydroxyl ends to be modified; and 
 adding the determined amount of the at least one acid to esterify the polar hyperbranched polymer; and 
 
 replacing a portion of the at least one linear thermoplastic polymer in the given coating with the at least one modified hyperbranched polymer thereby reducing the amount of the at least one added solvent needed in the coating and thereby reducing Volatile Organic Compounds therein while also lowering viscosity of the given coating; and 
 wherein the at least one modified hyperbranched polymer replaces up to about 13% of the least one thermoplastic polymer in the given coating. 
 
     
     
       11. The method of  claim 10 , wherein the at least one modified hyperbranched polymer replaces about 2% to about 6% by weight of the thermoplastic polymer in the given coating. 
     
     
       12. The method of  claim 10 , wherein the at least one thermoplastic polymer comprises about 70% to about 85% solids. 
     
     
       13. The method of  claim 10 , wherein the polar hyperbranched polymers comprise hyperbranched polymers with OH terminal functional groups and having a hydroxyl functionality between 16 and 128. 
     
     
       14. The method of  claim 10 , wherein the at least one acid is selected from the group consisting of propionic acid, hexanoic acid, octanoic acid, and decanoic acid. 
     
     
       15. The method of  claim 10 , wherein the coating having reduced VOCs comprises:
 the at least one pigment in an amount between about 28% to about 32% by weight of the coating; 
 the at least one thermoplastic polymer in an amount between about 34% to about 39% by weight of the coating, including the portion thereof replaced by the at least one modified hyperbranched polymer; and 
 the at least one added solvent in an amount between about 15% to about 20% by weight of the coating. 
 
     
     
       16. The method of  claim 10 , wherein the coating having reduced VOCs comprises:
 the at least one pigment in an amount between about 33% to about 39% by weight of the coating; 
 the at least one thermoplastic polymer in an amount between about 35% to about 40% by weight of the coating including the portion of the at least one thermoplastic polymer replaced by at least one modified hyperbranched polymer; and 
 the at least one added solvent in an amount between about 20% to about 25% by weight of the coating. 
 
     
     
       17. A method of reducing Volatile Organic Compounds in a given coating based on at least one linear thermoplastic polymer, at least one added solvent and at least one pigment, comprising the steps of:
 modifying the polarity of at least one hydroxyl terminated hyperbranched polymer to make at least one modified hyperbranched polymer, wherein modifying the polarity of the hyperbranched polymer comprises:
 providing a polar hydroxyl terminated hyperbranched polymer, the hyperbranched polymer having a viscosity lower than a viscosity of the linear thermoplastic polymer; 
 determining a number of hydroxyl ends in the hyperbranched polymer; 
 determining a percentage of the hydroxyl ends to be modified; 
 determining a stoichiometric amount of at least one acid to be used to modify the polar hydroxyl terminated hyperbranched polymer, the stoichiometric amount being calculated according to the number of hydroxyl ends in the hyperbranched polymer and the percentage of hydroxyl ends to be modified; and 
 adding the determined amount of the at least one acid to esterify the polar hyperbranched polymer; and 
 
 replacing a portion of the at least one linear thermoplastic polymer in the given coating with the at least one modified hyperbranched polymer thereby reducing the amount of the at least one added solvent needed in the coating and thereby reducing Volatile Organic Compounds therein while also lowering viscosity of the given coating; 
 wherein the coating having reduced Volatile Organic Compounds comprises:
 the at least one pigment in an amount between about 28% to about 32% by weight of the coating; 
 the at least one thermoplastic polymer in an amount between about 34% to about 39% by weight of the coating, including the portion thereof replaced by the at least one modified hyperbranched polymer; and 
 the at least one added solvent in an amount between about 15% to about 20% by weight of the coating. 
 
 
     
     
       18. A method of reducing Volatile Organic Compounds in a given coating based on at least one linear thermoplastic polymer, at least one added solvent and at least one pigment, comprising the steps of:
 modifying the polarity of at least one hydroxyl terminated hyperbranched polymer to make at least one modified hyperbranched polymer, wherein modifying the polarity of the hyperbranched polymer comprises:
 providing a polar hydroxyl terminated hyperbranched polymer, the hyperbranched polymer having a viscosity lower than a viscosity of the linear thermoplastic polymer; 
 determining a number of hydroxyl ends in the hyperbranched polymer; 
 determining a percentage of the hydroxyl ends to be modified; 
 determining a stoichiometric amount of at least one acid to be used to modify the polar hydroxyl terminated hyperbranched polymer, the stoichiometric amount being calculated according to the number of hydroxyl ends in the hyperbranched polymer and the percentage of hydroxyl ends to be modified; and 
 adding the determined amount of the at least one acid to esterify the polar hyperbranched polymer; and 
 
 replacing a portion of the at least one linear thermoplastic polymer in the given coating with the at least one modified hyperbranched polymer thereby reducing the amount of the at least one added solvent needed in the coating and thereby reducing Volatile Organic Compounds therein while also lowering viscosity of the given coating; 
 wherein the coating having reduced Volatile Organic Compounds comprises:
 the at least one pigment in an amount between about 33% to about 39% by weight of the coating; 
 the at least one thermoplastic polymer in an amount between about 35% to about 40% by weight of the coating including the portion of the at least one thermoplastic polymer replaced by at least one modified hyperbranched polymer; and 
 the at least one added solvent in an amount between about 20% to about 25% by weight of the coating.